1. Field of the Invention
This invention relates in general to surgery and specifically to bone-tendon-bone graft harvesting for knee ligament reconstruction. It would be found in the patent files in a classification for surgical bone cutting implements.
2. Prior Art
There has long been a need for a more efficient means of harvesting the graft for ACL reconstruction of the knee. In such surgery a graft consisting of a portion of tibia bone, a portion of patella tendon and another bone portion from the patella is removed from the knee of the patient and arthroscopically relocated inside the knee to replace a damaged anterior cruciate ligament (ACL). Historically the preferred method of bone portion removal has been with osteotomes (chisels), leaving irregular pieces of bone which then have to be trimmed and sized by hand to the approximate shape of cylinders for fitting into the drilled out tibial and femoral tunnels inside the knee.
In order to more efficiently harvest the graft, introduce less trauma at the donor site and provide for a better bone plug/drilled tunnel fit, the ACL bone saw was developed (U.S. Pat. No. 5,092,875). The ACL bone saw peripherally oscillates a ring of teeth about its center by means of an attached drive arm. Thus the ACL saw is substantially different from a standard plug cutter in that it has no shaft and therefore can easily be inserted into pre-cut notches in the tibia and patella for removal of cylindrical bone plugs.
A device from Australia called the Helical Tube Saw has also been developed to harvest the graft. It appears much the same as a standard plug cutter with the exception of an additional helical slot open ended at the teeth and running longitudinally along the tube. Such a configuration allows the cutting tube to wrap around the tendon portion of the graft as it cuts the bone portion from the proximal end (tendon end first) with the knee flexed to 90 degrees. The device must be oscillated by hand and the complexity of the blade hinders its use as a one-time only disposable item.
However, from a physician's standpoint, it is desirable to initiate the bone cut from the tendon end rather than the distal bone plug end. Also, if the ACL bone saw could be made to cut in that direction, it would further reduce trauma at the donor site by eliminating the need for pre-cut blade insertion notches.